1 88 BOTANICAL GAZETTE. [ August 



exospore is thinner and yellowish-brown in color, and appar- 

 ently somewhat papillate, but the markings are masked by 

 those of the overlying oogonium wall, and as the specimens 

 examined were not quite mature, it was difficult to free the 

 oospores from the oogonia. The markings of the exospore 

 are certainly much less prominent than in C. candidus. 



As the oogonia and oospores differ decidedly from those 

 of C. cubicus, called in recent works C. Tragopogonis (Pers.) 

 Schroeter, the present form can not be included in that 

 species, to which it was referred in 1874 m Grevillea, iii. 58, 



and where it is still placed in Saccardo's Sylloge Fungorum, 

 vii. 234, 1888. In 1883 Zalewski in Bot. CcniralbL, xv. 223, 

 under the name of C. Convolvulacearum Otth, described the 

 oospores of the Cystopus on Convolvulus Siculus in Southern 

 France, and on C. retusus in Guadeloupe, and referred the 

 North American form on Ipomoea Batatas to the same 

 species, although he had not seen oospores in the latter 

 case ; and Zalewski's name was adopted by Kellerman in 

 Trans. Kansas Acad. Sci. x. 94, and by Ellis in N. A. F. 

 no. 1809. Being unable to ascertain where the name cited 

 by Zalewski was originally published by Otth, I applied for 

 information to Dr. Ed. Fischer, of Berne, who kindly in- 

 formed me that there were specimens in the Otth herbarium 

 marked C. Convolvidi Otth on C. Siculus from Hyeres, but 

 that he was unable to find out when or where the species was 

 published by Otth. Probably the name of Otth is a manu- 

 script name, and we may regard Zalewski as the proper au- 

 thority for the name C. Convolvulacearum, which name is 

 not quoted in the Sylloge of 1888. The description of Zalew- 

 ski makes no mention of the characteristic papillate oogonia, 

 and his account of the markings of the oospores does not 

 agree with those seen in Prof. Pammel's specimens, but when 

 quite mature the latter might have become more distinctly 

 marked. 



Undoubtedly the first name given to the form on 

 Convolvidacece in North America was sEcidiimi Ipomcnr- 

 fanduranm Schweinitz, for an examination of an au- 

 thentic specimen of Schweinitz shows that it is certainly 

 a Cystopus identical, so far as can be told by the con- 

 ldia, with the Cystopus known in this country on Ifo- 

 mma Batatas Lam., /. Jala fa Pursh., /. panduraia 

 Meyer, /. leftofhylla Torn, /. commutata Roem. & Sch., 

 /. iltf/Roth., and /. hederacea Jacq. To this form is appar- 

 ently also to be referred the Cystopus reported by me (Bo- 

 tanical Gazette, viii. 335), as growing on cotton leaves in 



